Long non-coding RNA HOTAIR is a marker for hepatocellular carcinoma progression and tumor recurrence

The present study aimed to investigate the expression level of HOX transcript antisense RNA (HOTAIR) in hepatocellular carcinoma (HCC) and its association with various clinicopathological characteristics, and to further explore the molecular mechanisms of HOTAIR function in HCC. Quantitative reverse transcription-polymerase chain reaction (RT-PCR) was used to detect the expression level of HOTAIR in 60 paired fresh HCC samples and adjacent normal liver tissue samples. The association between HOTAIR expression and clinicopathological parameters was analyzed. Lentivirus-mediated HOTAIR-specific small hairpin RNA vectors were transfected into HepG2 cells. Cell proliferation and invasion in vitro were examined by MTT and Transwell assays, respectively. A xenograft model was used to analyze the tumorigenesis of liver cancer cells in vivo. In addition, semi-quantitative RT-PCR was used to detect the expression level of Wnt/-catenin signaling molecules under the condition of HOTAIR inhibition. The results revealed that the expression level of HOTAIR in HCC tissues was higher than that in adjacent non-cancerous tissues. HOTAIR expression was significantly associated with poor tumor differentiation (P=0.002), metastasis (P=0.002) and early recurrence (P=0.001). In vitro, the inhibition of HOTAIR in liver cancer cells resulted in the suppression of cell proliferation and invasion. HOTAIR depletion significantly inhibited the rate of growth of liver cancer cells in vivo. Furthermore, the expression levels of Wnt and -catenin were downregulated when HOTAIR expression was suppressed. In conclusion, HOTAIR is important in the progression and recurrence of HCC, partly through the regulation of the Wnt/-catenin signaling pathway. Targeting HOTAIR may be a novel therapeutic strategy for HCC.